Triangular rule



Patented Jan. 7, 1890.

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TRIANGULAR RULE.

(MMM) F. BBNZINGBR au H. E'. GRABAU.

WTVESSES.'

@www W UNITED STATES PATENT OFFICE.

FREDERICK BENZINGER, OE NE\V YORK, N. Y., AND HANS EDGAR GRABAU,

l OF I-IOBOKEN, NEW JERSEY.

TRIANGULAR RULE.

SPECIFICATION forming part of Letters Patent No. 418,967, dated January7, 1890.

Application filed September 26, 1889. Serial No. 325,202. (No model.)

To @ZZ whom it may concern:

Be it known that we, FREDERICK BENZING- ER, of the city, county, andState of New York, a citizen of the United States, and HANS EDGARGRABAU, of Hoboken, in the county of Hudson aud State of New Jersey, acitizen of the German Empire, have invented certain new and usefulImprovements in Rules, ot which the following is a specification.

1o This invention relates to improvements in the rules of triangularcross-section, such as are used by draftsmen, engineers, architects, &c.These rules are usually made of boxwood, which is very light and veryapt to warp,

especially if the scale is of considerable len gth.

The object of our invention is to provide a rule of this kind which isweighted, so as to be heavier than the ordinary7 box-wood rule.

The further object of our invention is to 2o prevent the warping of therule, and another object of our invention is to provide an indicatorwhich shows which scale on the rule is being used.

The invention consists in a draftsmans rule 2 5 of triangularcross-section, provided with a reentorcing tube or rod extendinglengthwise through the same for the purpose of weighting the scale, andalso to provide against warping and bending.

3o rlhe invention Jfurther consists in the combination, with anindicator provided at the end of the rule and which can be adjusted topoint to any one, of the scales on the rule.

The invention also consists in the construc- 3 5 tion and combination ofparts and details, as will be fully described hereinafter, and finallypointed out in the claims.

In the accompanying drawings, Figure l is a face View of our improveddraftsmans rule,

4o parts being broken out and others shown in longitudinal section. Fig.2 is a transverse sectional view of the same on the line Ei g. I. Fig. 3is a similar transverse sectional View showing a modication.

Similar letters of reference indicate corre' sponding parts.

The rule A, which is preferably made of boxwood, but can be made ofother suitable material in cross section, has the shape of anequilateral triangle, and on each side is pro- 5o vided with twograduated scales-one at each edge of each side-in the usual manner. Therule is provided with a central longitudinal bore B, in which a metaltube O is inserted, said tube serving toincrease the weight of the rule,and also serving to prevent bending and warping. In. place of the tube,a rod D may be inserted in the bore B, as shown in Fig. 3. A cylindricalpiece E is inserted in one end of the tube O in such a manner that itcan turn 6o in the same, and on the end of said piece E the indicator Eis hinged. Then thehinged pieces E and F are swung in line, they bothcan be inserted into the tube B, so as to be out of the way.

When the rule is being used, the piece F is drawn out sufficiently topermit of its being swung upward, and then it and the piece E in thetube O are so turned that said piece F rests against or is adjacent tothe end of that 7o scale that is being used, so that if by accident therule is overturned or placed in another position the draftsman can atonce tell which of the scales he has been using.

Having thus described our invention, we claim as new and desire tosecure by Letters Patentl. A draftslnans rule made triangular incross-section and provided with a longitudinal metal tubularfilling-piece surrounded by 8o the material of which the rule is made,substantially as setforth.`

2. The combination, with a drattsmans rule having an aperture in theend, of a plug adapted to be inserted in said aperture and 8 5 anindicator hinged to said plug, substantially as set forth.

In testimony that we claim the foregoing as our invention we have signedour names in presence of two subscribing Witnesses;

'itnesses:

OSCAR F. GUNZ, INI. REIMHERR.

